xcii. Appendix: — Proceedings of 



dust-like ova to a distant plant, upon which they propagate 

 their species, and are again destined to spread themselves in a 

 similar manner. But by far the most constant mode of dis- 

 persing themselves is afforded by the close proximity of one 

 Coffee plant to another ; and although they may not be so 

 closely planted as to touch each other, the presence of weeds 

 upon the Estate must afford them an equally easy transit. 

 And when it is known from the calculations of Reaumer, 

 a Naturalist who devoted a good deal of time to such pur- 

 suits, that one Aphis, a creature about one-sixth of the size 

 of the Bug, may be the progenitor of several millions of 

 descendants in an incredibly short space of time, the rapid 

 propagation of this pest may be satisfactorily accounted for. 



It is during the period that the insect is in a locomotive 

 state and for a short time after, whilst the ova are being 

 matured, that the injury is done to the tree. Being provided 

 with a sucking apparatus called hostellum by naturalists, and 

 probably furnished with a secretion from its body, it pierces 

 the cutis of the leaf, irritates the surface of the plant, and 

 causes it to furnish a juice upon which it feeds; it is this irri- 

 tation, coupled with the closing of the breathing pores of the 

 leaf, whereby respiration is prevented, that causes so much 

 injury to the plant, which literally becomes suffocated and 

 exhausted, and all its functions impaired. 



To give an idea of the ravages of this pest were almost 

 needless ; its mysterious commencement and disappearance, 

 its attacking a particular part of an Estate and leaving the 

 rest untouched, the various efforts that have been made to 

 destroy it, the pertinacity with which it withstands them all, 

 and the gradual manner in which it spontaneously disappears 

 when left alone, are all familiar to every one conversant with 

 Coffee planting; but with the knowledge of the structure and 

 habits of the insect just detailed, it need no longer be a matter 

 of wonder and surprise how an Estate becomes so rapidly or 

 so mysteriously attacked, or why the remedies hitherto pro- 

 posed should have proved inefficient ; though it may still 



